1. Field of the Invention
This invention relates to a multi-element holding structure for holding a plurality of elements mounted on a base plate, and more particularly to a multi-element holding structure for integrally holding a heat generative element and a heat sensitive capable of sensing heat generated by the heat generative element
2. Description of the Related Art
Heat generative elements such as transistors mounted on a base plate, when they are excessively heated, may lead to thermal runway to be short-circuited, thereby adversely affecting electronic appliances. In order to obviate such an inconvenience, a heat-sensitive element such as a temperature fuse and temperature sensor capable of sensing the temperature of the heat-generative elements are mounted to be in intimate contact with the heat-generative elements and mounted on the base plate.
FIG. 5 is a sectional view showing a conventional multi-element holding structure for holding heat generative elements and a heat sensitive element. Mounted on a base plate 5 are heat-generative elements 2, 3 of transistors and a heat sensitive element 4 of a temperature fuse. The heat sensitive element 4 is sandwiched between the two heat generative elements 2, 3. The outer walls of the heat-generative elements 2, 3 are covered with a thermal compression tube 6.
The thermal compression tube 6 is made of heat-sensitive resin formed in a cylindrical shape. When the heat generative elements 2, 3 and heat sensitive element 4, after passed into the cylindrical thermal compression tube 6, are heated, the thermal compression tube 6 shrinks to be brought into intimate contact with the heat-generative elements 2, 3. Thus, the heat generative elements 2, 3 and the heat sensitive element 4 are integrally held. The heat sensitive element 4 kept in intimate contact with the heat generative elements 2, 3 is adapted to able to detect the temperature of the heat-generative elements 2, 3 accurately, as disclosed in JP-UM-A-64-48047.
However, the above conventional multi-element holding structure presented a problem of increasing the number of assembling man-hours because of necessity of heating the thermal compression tube 6. Further, if the width in a direction perpendicular to paper face of the heat-sensitive element 4 is narrower than that of the heat-generative elements 2, 3, the heat sensitive element 4 is prone to come off upward. This presented such a problem that packaging of the base plate after integration is not easy, thereby increasing the number of assembling man-hours.